Accuracy of the Accuro 3S

Feasibility will be assessed in terms of how easily the device can be used and if it poses any discomfort to the patient. Live guidance is defined as the ability to see and change, if needed, the needle trajectory as it is advanced. Accuracy is defined as a measurement of depth by device versus the actual depth of the needle, number of needle attempts (skin punctures) and number of needle redirection.

Inclusion criteria

• The anesthetic plan for the patient includes a neuraxial anesthetic (spinal or epidural) as the main anesthetic for labor, surgery (e.g. orthopedic surgery, cesarean delivery) or for postoperative pain management (e.g, major abdominal surgery). *Given our labor and delivery volume (~300 epidurals/month) investigators think that they will only recruitc obstetric patients. In case of difficulty recruiting, then investigators will seek out a different patient population.
• No history of allergic reactions to adhesives used in standard epidural placements as per chart review or self-reported.
• Patient skin is intact in the area of placement of the epidural or spinal anesthesia.
• The patient is English speaking.
• For obstetric patients, the patient is admitted for cesarean delivery or for induction and is not in active labor. *Clarification - Patients scheduled for elective cesarean delivery will be approached for spinal anesthesia. Given that spinal anesthesia carries a smaller risk for post-dural puncture headache and other morbidities, investigators will recruit and perform 10 spinals on this patient population. Once comfortable with the technology, then will move to recruiting and performing epidurals. If during the spinal anesthesia trial the device does not provide accurate and clear needle visualization, the study will be culminated.

Exclusion criteria

• Contraindication to epidural catheter placement including bleeding diathesis (essential thrombocythemia, idiopathic thrombocytopenic purpura, von Willebrand disease, and hemophilia A or B), neurological dysfunction (multiple sclerosis, subacute myeloopticoneuropathy or preexisting lower limb neurological deficit), prior extensive spinal surgery or major spinal deformity, pre-operative use of anti-coagulant with planned use of therapeutic dose of anti-coagulant in post-operatively, documented pre-operative coagulopathy (INR greater than 1.3 not on Coumadin or PTT greater than 42), platelets less than 100, 000, or evidence of infection at potential epidural site.
• Presence of orthopedic implants in the spine.
• Skin dyscrasias or allergies to the ultrasound procedure.
• Unable to assume sitting position.
• Body Mass Index (BMI) less than 18.5 kg/m2.